Of all the things you could critique DSA on, this is the hill you're going to die on? 
DSA deciding to do a mask mandate at this event is unequivocally good and based. Shut the fuck up, you fucking dipshits.
Imagine being this much of a fucking goddamn crybaby about masking. Eat shit, you ableist fucks.
One of the biggest lessons this pandemic has taught me is the astounding number of people for whom leftism is really just performative, and that when push comes to shove, these people will make the biggest fucking stink about having to do something even mildly inconvenient for even a single fucking event or context and show themselves for who they really are.
Sorry to hear about your experiences, comrade. It sounds really frustrating. Ive been put off by orgs before and it feels like a real defeat.
Maybe I'll learn the same lessons, but this is where my journey has led me so far. And we have helped people form unions and take actions against their bosses, and tonight the mobilized left in my state scored an honest to god (intermediate) victory for reproductive care access. Theres the fight for lgbtq+ especially attacks on trans people. Maybe I can't change the org but I can organize locally and work with a crew. And I'm in a caucus so I do participate in national DSA politics. Dont hold your breath but the org is changing. I guess what is yet to be seen is what kind of reaction will there be, and from where?